Differentiate $f ( x ) = \left( x ^ { 2 } + 1 \right) ( x + 6 )$

Multiple Choice

Differentiate: $f ( x ) = \left( x ^ { 2 } + 1 \right) ( x + 6 )$

A) $x ^ { 2 } + 1$
B) $3 x ^ { 2 } + 12 x + 1$
C) 2x + 1
D) 12x + 1